diff --git a/ws2012/P2P/uebungen/4/src/common/MessageType.java b/ws2012/P2P/uebungen/4/src/common/MessageType.java
index 6571706f..4673767f 100644
--- a/ws2012/P2P/uebungen/4/src/common/MessageType.java
+++ b/ws2012/P2P/uebungen/4/src/common/MessageType.java
@@ -6,4 +6,7 @@ public class MessageType {
 
 	public final static byte NEW_NEIGHBOR_IPV4 = 4;
 	public final static byte NEW_NEIGHBOR_IPV6 = 6;
+
+	public final static byte PING = 2;
+	public final static byte PONG = 3;
 }